In a package or article sorting conveyor, for example, of the type disclosed in U.S. Pat. No. 5,027,939 which issued to the assignee of the present invention, an elongated frame supports an endless flexible apron or carrier which includes a pair of parallel spaced endless chains connected by parallel spaced cross slats or tubes. A series of article transfer units or pushers are supported by adjacent pairs of the cross tubes for lateral sliding movement between the drive chains of the carrier. Each of the pushers on the top run of the carrier includes a downwardly projecting shaft which carries one or more followers or rollers for engaging a track system supported within the frame and including a set of switch blocks.
Each of the switch blocks is supported for pivotal movement on a vertical axis and is pivoted by a remotely controllable actuator in the form of a fluid cylinder or solenoid. When it is desired to move a series of pushers laterally on their supporting cross slats or tubes for shifting a package or article transversely across the carrier to a receiving bin or spur conveyor, a switch block is pivoted to direct the rollers of the pushers along a track which extends transversely across the width of the endless carrier.
As apparent from the above mentioned U.S. Pat. No. 5,027,939, when a switch block is pivoted for diverting a series of pushers, there is an abrupt change in the direction of movement of each pusher as its corresponding roller passes through the switch block. This requires that the pivoting of the switch block be rapid and precisely timed with the movement of the endless carrier. It is also desirable for the switching system to be constructed for minimizing noise and wear on the switching and diverting system, all of which become more of a problem with higher speed operation of the conveyor.